Field of the Invention
The present invention relates to a pressure-sensitive adhesive sheet.
Background
A pressure-sensitive adhesive sheet excellent in airtight performance has been known. An example of the pressure-sensitive adhesive sheet is a pressure-sensitive adhesive sheet used in a magnetic disc device (see, for example, JP 2014-162874A). A pressure-sensitive adhesive sheet of this kind is used, for example, for covering a narrow gap made between a box-form base part which a magnetic disc device has, and a plate-form cover part attached to this base part. By covering the gap with the pressure-sensitive adhesive sheet in this way, the airtight performance of the inside of the magnetic disc device is kept.
A pressure-sensitive adhesive sheet of this type is also used to cover a filling-opening through which a low-density gas (such as helium) is filled into a magnetic disc device. As disclosed in JP 2010-3356A, the magnetic disc device may be a device into which a low-density gas is filled in order to restrain, for example, the disturbance of air flow that is generated when the device is driven. In such a magnetic disc device, filling-opening thereof is covered with a pressure-sensitive adhesive sheet in order for the low-density gas not to leak to the outside, after the magnetic disc device being filled with the low-density gas.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2014-162874
Patent Document 2: Japanese Unexamined Patent Application Publication No. 2010-3356